CVE-2026-27903 in minimatch
Summary
by MITRE • 02/26/2026
minimatch is a minimal matching utility for converting glob expressions into JavaScript RegExp objects. Prior to version 10.2.3, 9.0.7, 8.0.6, 7.4.8, 6.2.2, 5.1.8, 4.2.5, and 3.1.3, `matchOne()` performs unbounded recursive backtracking when a glob pattern contains multiple non-adjacent `**` (GLOBSTAR) segments and the input path does not match. The time complexity is O(C(n, k)) -- binomial -- where `n` is the number of path segments and `k` is the number of globstars. With k=11 and n=30, a call to the default `minimatch()` API stalls for roughly 5 seconds. With k=13, it exceeds 15 seconds. No memoization or call budget exists to bound this behavior. Any application where an attacker can influence the glob pattern passed to `minimatch()` is vulnerable. The realistic attack surface includes build tools and task runners that accept user-supplied glob arguments (ESLint, Webpack, Rollup config), multi-tenant systems where one tenant configures glob-based rules that run in a shared process, admin or developer interfaces that accept ignore-rule or filter configuration as globs, and CI/CD pipelines that evaluate user-submitted config files containing glob patterns. An attacker who can place a crafted pattern into any of these paths can stall the Node.js event loop for tens of seconds per invocation. The pattern is 56 bytes for a 5-second stall and does not require authentication in contexts where pattern input is part of the feature. Versions 10.2.3, 9.0.7, 8.0.6, 7.4.8, 6.2.2, 5.1.8, 4.2.5, and 3.1.3 fix the issue.
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Analysis
by VulDB Data Team • 06/02/2026
The vulnerability described in CVE-2026-27903 represents a critical denial of service weakness in the minimatch library, a widely used utility for pattern matching in Node.js environments. This issue stems from the `matchOne()` function's implementation which exhibits unbounded recursive backtracking when processing glob patterns containing multiple non-adjacent GLOBSTAR segments. The flaw manifests when a glob pattern with multiple `**` wildcards is applied against input paths that do not match the pattern, creating exponential time complexity that can quickly overwhelm system resources. The vulnerability is particularly dangerous because it operates without any built-in safeguards such as memoization or call budgeting mechanisms to limit execution time, making it susceptible to exploitation in scenarios where user input controls pattern matching operations.
The technical implementation of this vulnerability can be categorized under CWE-400, which specifically addresses uncontrolled resource consumption, and more precisely aligns with CWE-770, concerning allocation of resources without limits or throttling. From an operational perspective, this vulnerability directly maps to ATT&CK technique T1496, which involves resource exhaustion through manipulation of system resources. The time complexity of O(C(n,k)) where n represents path segments and k represents globstars creates a mathematical explosion in processing time, with practical impacts becoming noticeable at relatively modest values such as k=11 requiring approximately 5 seconds and k=13 exceeding 15 seconds of processing time. This exponential growth makes the vulnerability particularly attractive to attackers seeking to disrupt service availability in environments where pattern matching is frequently invoked.
The attack surface for this vulnerability extends across numerous Node.js applications and development tools that rely on glob pattern matching for configuration management, file filtering, and build automation tasks. Build tools such as ESLint, Webpack, and Rollup are particularly at risk since they commonly accept user-supplied glob arguments that can be manipulated to trigger the vulnerable code path. Multi-tenant systems present another significant exposure vector where one tenant could configure glob-based rules that execute within a shared process, potentially affecting other tenants. Administrative interfaces that accept ignore-rule or filter configurations as globs, along with CI/CD pipelines that process user-submitted configuration files, create additional attack vectors where unauthenticated attackers could inject malicious patterns to cause system stalls. The impact of this vulnerability is measured not just in computational time but in event loop blocking that can effectively render applications unresponsive for tens of seconds per invocation, severely impacting system availability and user experience.
The remediation for this vulnerability involves upgrading to the patched versions of minimatch including 10.2.3, 9.0.7, 8.0.6, 7.4.8, 6.2.2, 5.1.8, 4.2.5, and 3.1.3, which contain the necessary fixes to eliminate the unbounded recursive backtracking behavior. Security practitioners should prioritize this update across all systems that utilize minimatch for glob pattern matching, particularly in environments where user input influences pattern creation. Organizations should also implement monitoring for suspicious pattern lengths and execution times in systems that process user-supplied glob expressions. Additionally, defensive programming practices should be adopted to validate and limit the complexity of glob patterns before processing, and to implement timeouts for pattern matching operations where possible. The vulnerability serves as a reminder of the importance of algorithmic complexity analysis in security-critical code paths and the necessity of implementing resource constraints to prevent exploitation of mathematical weaknesses in pattern matching algorithms.